This invention is directed to a new and improved keyboard assembly which provides tactile feel, is easily assembled, is sealed in such a manner that particles of food, dust or liquids are preventing from accumulating between parts of the frame thereof and the keys of the keyboard and the finger manipulated portions thereof are easily cleaned by wiping a damp cloth or the like over the top thereof.
In the food handling industries such as supermarket meat departments, there has developed the need for a keyboard as part of a price marking unit, calculator or the like that can easily be kept clean. Unfortunately, most of the prior art keyboards utilize conventional keys positioned and extending up from a frame and thus food particles and dirt tend to wedge between the frame and the keys. See examples in U.S. Pat. Nos. 3,721,778, 3,705,276 and 3,780,237.
While there are some flat type keyboard assemblies such as shown in U.S. Pat. No. 3,721,778, this construction also usually includes frames over the flat depressible portions and thus is also difficult to keep clean. Such flat keyboard structures also do not provide the tactile feed provided by this invention.
Some prior art keyboards have been at least partially covered or closed but these keyboards have been of a different construction than the present invention and thus do not provide the type of tactile feel to the user achievable with the device of this invention. Reference may be had to U.S. Pat. Nos. 3,743,797, and 3,699,294 which illustrate covered types of keyboard construction.
More particularly, the present invention is an improvement over the keyboard assembly shown in U.S. Pat. No. 3,860,771 (FIG. 19) and is particularly adapted for use in instances where cleanliness of the operable (finger touched) parts of the keyboard is mandatory.
The construction of the preferred form of the present invention also departs from U.S. Pat. No. 3,860,771 in that it permits the use of more simply constructed frames and buttons or cores, and the cores are held within the bores of the frame by the keyboard top sealed to the top of the frame.
In addition, the keyboard of this invention which discloses a rigid core under a top provides improved key click acoustical feedback so that the user can more readily ciscern by sound as well as feel the fact that the key has been depressed.